Bhopal: Five-time world champion MC Mary Kom of Manipur stormed into the semifinals of the flyweight division at the 12th senior women's national boxing championship on Friday.

Mary boxed her way into last four stage of the 51kg category with a comprehensive 17-0 win over P Nirosha of Andhra Pradesh.

Mary, the 2010 Asian Games bronze medallist, was leading 17-0 when the referee decided to stop the fight and spare the Andhra Pradesh girl of any further distress.

"It was a good victory for me and I had a good rhythm going on. I am happy with the way I have been performing and hope to carry the same form into the semis and most likely the finals as well," Mary said.

L Sarita Devi (51kg) also advanced to the semifinals in the flyweight division.

The former world champion was expected to have a tough battle for a place in the semis against Vanlal Duati of Mizoram, who won the gold medal in the 48kg at the 2011 National Games.

But Sarita, who is playing for the All India Police team, was at her riveting best as she tore apart Duati's defence.

After the opening two minutes of play the score was level at one-all, but with the beginning of the next round Sarita shifted gears and started increasing the margin.

She scored six and seven points in the second and third rounds respectively with Duati only managing four in both.

The final two minutes of play and Sarita launched an offensive onslaught on a worn out Duati. The 29-year-old was relentless with her straight punches and jabs and won the round 12:3 and with it the bout 26:13.

In the same weight category, Pinki Jangra (51kg) of Haryana continued her purple patch as she stormed into the semifinals, beating local boxer Nirmala Kohli, who retired hurt after taking some heavy pounding.

Sarita will take on National Games gold medallist Pinki Jangra in the semifinal, while Mary will be up against Dolly Singh of West Bengal in other last four bout.